Apparatus and assembly for heating pipes

Abstract

A heater is provided for a waste water system comprising of a heating element encased in a protective pipe. The pipe is closed at one end and attached at the opposite end to an end cap that may be connected by a standard fitting to a sewer installation. The protective pipe is sealed to the end cap and the heating element is removable from within the protective pipe without adversely affecting the integrity of the installation.

The invention claimed is: 
     
       1. A heating assembly for insertion in to a conduit of a water system consisting of a heating element, a protective pipe encasing at least part of said heating element, said protective pipe closed at one end and attached at the opposite end to a retainer dimensioned to be connected to a fitting of a water system, said protective pipe defining a chamber to contain said heating element and separate said heating element from said conduit, a bore extending through said retainer to receive slidably said protective pipe and permit longitudinal adjustment of said protective pipe relative to said retainer and thereby vary the length of protective pipe inserted in to said conduit, and a compressive clamp applying a radial force between said retainer and said protective pipe to cause said retainer to engage said protective pipe and inhibit relative movement between said protective pipe and said retainer and seal said protective pipe to said fitting, said heating element passing through said bore so as to be removable from within the protective pipe whilst maintaining the integrity of said conduit. 
     
     
       2. The heating assembly of  claim 1  wherein said heating element is connected to a power supply adjacent to the opposite end of the protective pipe to said one end and the connection protected by a seal assembly. 
     
     
       3. The heating assembly of  claim 2  wherein said seal assembly includes a first seal to cover said connection between said power supply and said heating element and a second seal between said power supply and said protective pipe. 
     
     
       4. The heating assembly of  claim 3  wherein said protective pipe extends in said bore from one side of said retainer to the other. 
     
     
       5. The heating assembly of  claim 4  wherein said first seal is located within said protective pipe. 
     
     
       6. The heating assembly of  claim 5  wherein said second seal is located on the opposite side of said cap to said one end of said protective pipe. 
     
     
       7. The heating assembly of  claim 6  wherein each of said seals includes a heat shrinkable sleeve. 
     
     
       8. The heating assembly of  claim 1  wherein said protective pipe is flexible. 
     
     
       9. The heating assembly of  claim 8  wherein said protective pipe is a plastics material. 
     
     
       10. The heating assembly of  claim 9  wherein said pipe is formed from a high density polyethylene. 
     
     
       11. The heating assembly of  claim 10  wherein said one end has a plug welded to said pipe to seal said one end. 
     
     
       12. The heating assembly of  claim 8  wherein said one end of said protective pipe is tapered. 
     
     
       13. The heating assembly of  claim 1  wherein said heating element is flaccid and is a close fit within said protective pipe to be supported by said protective pipe. 
     
     
       14. The heating assembly of  claim 13  wherein said heating element is a self-regulating heating cable. 
     
     
       15. The heating assembly of  claim 1  wherein said retainer is a push fit in said fitting to permit said heater assembly to be inserted in said water system without rotation. 
     
     
       16. The heating assembly of  claim 15  wherein said retainer is adapted to be mechanically secured to said fitting and selectively releasable therefrom. 
     
     
       17. The heating assembly of  claim 1  wherein said retainer is releasably secured to said fitting to permit relative rotation between said fitting and said retainer. 
     
     
       18. The heating assembly of  claim 17  wherein said retainer is incorporated in to a strain relief assembly. 
     
     
       19. The heating assembly of  claim 1  wherein said protective pipe is locally reinforced in the vicinity of said retainer. 
     
     
       20. The heating assembly of  claim 19  wherein a sleeve is inserted within said protective pipe to resist radial loads applied to said pipe.